The present invention relates to an improvement of a plow or harrow of the type in which a plurality of saucer-shaped disks attached at an angle with respect to the direction of travel of a tractor to one axle or gang bolt such that these disks are forcibly rotated to plow an uncultivated field.
In general, the plowing by a plowing machine may be divided into the so-called "horizontal travel" in which, as shown in FIG. 1, both the right and left wheels of a tractor travel on an uncultivated land and the so-called "inclined travel" in which, as shown in FIG. 2, only the right wheels of the tractor are dropped into a furrow so that the furrow wall acts as a guide for the wheels in the furrow. In the case of the horizontal travel, an operator will not be tired because of the tractor being maintained horizontal; however, during forward travel especially on inclined and rough farm lands, the operator must expend great care in maintaining the tractor in a desired direction so as to avoid plowing again the plowed field. In the case of the inclined travel, the direction of travel of the tractor can be easily controlled since the right wheels are guided by the furrow wall. However, the operator will be tired because of the tractor being inclined to the right. Thus, the horizontal travel and the inclined travel have their own merits and demerits so that an operator chooses the horizontal travel or the inclined travel depinding upon his or her skill and upon the conditions of a farm land to be cultivated.
In view of the above, the present invention has for its object to provide a plow or harrow which can easily plow and in which the angle of disks can be easily adjusted.